BIOC58H3 Lecture Notes - Lecture 7: Genetic Drift, Sickle-Cell Disease, Relate
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Whe(cid:374) a(cid:374) allele is (cid:858)fi(cid:454)ed(cid:859) that(cid:859)s the o(cid:374)l(cid:455) allele i(cid:374) the populatio(cid:374) Can fix good alleles just as equally as bad alleles. Heterozygotes can have the heterozygote advantage if you have recessive deleterious alleles that are bad for you, they hide in the heterozygote. Also, sometimes heterozygotes may have some advantages over homozygotes such as sickle cell. Consequence of genetic drift is reduction in genetic variation. Dominant deleterious genes tend to be weeded out faster. Inbreeding is short term because they go extinct, and more are hidden after. Genetic purging weeding out the bad alleles by natural selection. Increased fitness of overall population, but little genetic variation. Specialist that have niche requirements if food goes away, so does the specialist. What(cid:859)s (cid:272)ausi(cid:374)g the (cid:271)ulk of e(cid:454)ti(cid:374)(cid:272)tio(cid:374) is ha(cid:271)itat loss. Negative dependency growth once it reaches carrying capacity individual fitness goes down struggling against intraspecific competition. Allee opposite positive dependency growth curve fitness goes down as population goes down.